// 图片验证码
export function captcha(number = 4){
    //先清空验证码的输入
    let code = "";
    //验证码的长度
    var codeLength = number;
    //随机数
    var random = new Array(0,1,2,3,4,5,6,7,8,9,'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');
    for(var i = 0; i < codeLength; i++) {
        //取得随机数的索引（0~35）
        var index = Math.floor(Math.random()*36);
        //根据索引取得随机数加到code上
        code += random[index];
    }
    return code
}